GENETIC DIVERGENCE IN SELECTED DURUM WHEAT GENOTYPES OF ETHIOPIAN PLASM

Wheat of both the tetraploid (Triticum durum Desf.) and hexaploid (Triticum aestivum L.), is the most important cereal crop in Ethiopia, ranking third in total production (17%) next to maize (Zea mays L.) and tef (CSA, 2002). Wheat covers a total arable land of 110,434 ha with average productivity of about 8.4 qt ha^-1, which is below the national average (14.4 qt ha^-1). A field experiment was conducted at the Sirinka Agricultural Research Centre, northeastern Ethiopia, to estimate the genetic divergence among indigenous durum wheat (Triticum durum Desf.) genotypes of diverse origin, and clustering them into homogenous groups for the hybridisation programme. Genetic divergence analysis was done based on multivariate analysis using Mahalanobis’s D² statistic, which grouped the durum wheat genotypes into ten clusters. The highest inter-cluster distance was between cluster-ll and cluster-lll (D² = 57.15). There was no correspondence between geographic and genetic distances, i.e., germplasms, collected from the same geographic area were placed into different cluster groups and those collected from different geographic regions were placed into the same cluster. The presence of significant genetic variability among the evaluated durum wheat genotypes suggests an opportunity for improvement of grain yield through hybridisation of genotypes from different clusters and subsequent selection from the segregating generations.